Wyze Thermostat with C-Wire Adapter turning AC compressor on when heat goes on

Whenever I first hooked up my thermostat (which required the c-wire adapter) the AC compressor would turn on whenever the heat turned on. I was able to locate the wire that controlled the ac compressor and disconnected it since it was/is winter here and AC was not critical. Now the weather is starting to turn and I need to get the AC working. The blue wire on the right in the attached photo is what I disconnected. Everything was hooked up exactly as it was before

Is your Hvac system a conventional or o/b (heat pump) ?

Because I made the mistake of thinking my system was convention and it was actually O/B (heat pump). It was causing the same thing to happen - wanted the heat, ac would pop on, wanted it colder it turned the heat on.

My solve was the wire I labeled as W was actually an O/B - my Honeywell unit made it look like it was W, go figure.

This video helped me solve this mix up.

Pretty sure it’s a conventional gas furnace. Before the Wyze Thermostat the AC would not come in when the heat ran. Just the gas furnace and the air handler.

do u have only 1 wire per terminal on the C wire adapter? Only 1 wire should be on each terminal on the adapter…post more pix

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Your Y wire that goes to the outside unit is likely plugged into the wyze adapter, not into the Y terminal on your furnace, Show a wider image, including the adapter and the actual thermostat wire bundles

I’m having the same issue

stick with your 1 thread, trying to reply to you in multiple places isn’t going to help.


additional wire connections outside of the actual furnace.

Thermostat wiring (per Wyze app setup instructions)

The AC compressor needs to be directly connected to the furnace board, not to the C adapter.
Take the white wire out of this wirenut and run an additional wire inside the furnace to it that goes to Y on the furnace. Reattach the light blue wire to C on your furnace.

Leave the humidifier where it is, didn’t need to draw it in.

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Thanks speadie. That did the trick.

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